Unix socket control interface

Control applications running in the same Linux OS should be able to communicate
with the DLT Daemon via a socket connection.
To be able to do that, the DLT Client library need to be extended. DLT
Clients connected via this UNIX socket are not handled as normal DLT
Clients and no log messages will be forwarded to them. This avoids
problems in situations when a control application is connected to the
DLT Daemon before any other 'real' DLT Client (e.g. DLT Viewer) is
connected. In this situations, all already stored log messages are
flushed to the control application and therefore lost, because the
control application most likely ignore all incoming messages besides the
one in which it is interested in.

Signed-off-by: Christoph Lipka <clipka@jp.adit-jv.com>

17 files changed, 440 insertions, 25 deletions

diff --git a/include/dlt/dlt_client.h b/include/dlt/dlt_client.h
index f1d1f4c..1dcc3a6 100644
--- a/include/dlt/dlt_client.h
+++ b/include/dlt/dlt_client.h
@@ -78,14 +78,23 @@
 #include "dlt_types.h"
 #include "dlt_common.h"
 
+typedef enum
+{
+    DLT_CLIENT_MODE_UNDEFINED = -1,
+    DLT_CLIENT_MODE_TCP,
+    DLT_CLIENT_MODE_SERIAL,
+    DLT_CLIENT_MODE_UNIX
+} DltClientMode;
+
 typedef struct
 {
     DltReceiver receiver;  /**< receiver pointer to dlt receiver structure */
     int sock;              /**< sock Connection handle/socket */
     char *servIP;          /**< servIP IP adress/Hostname of TCP/IP interface */
     char *serialDevice;    /**< serialDevice Devicename of serial device */
+    char *socketPath;      /**< socketPath Unix socket path */
     speed_t baudrate;      /**< baudrate Baudrate of serial interface, as speed_t */
-    int serial_mode;       /**< serial_mode Serial mode enabled =1, disabled =0 */
+    DltClientMode mode;    /**< mode DltClientMode */
 } DltClient;
 
 #ifdef __cplusplus
diff --git a/src/console/dlt-control.c b/src/console/dlt-control.c
index 49b7de8..15a1435 100644
--- a/src/console/dlt-control.c
+++ b/src/console/dlt-control.c
@@ -424,9 +424,9 @@ int main(int argc, char* argv[])
     dlt_client_register_message_callback(dlt_receive_message_callback);
 
     /* Setup DLT Client structure */
-    g_dltclient.serial_mode = dltdata.yflag;
+    g_dltclient.mode = dltdata.yflag;
 
-    if (g_dltclient.serial_mode==0)
+    if (g_dltclient.mode==DLT_CLIENT_MODE_TCP)
     {
         for (index = optind; index < argc; index++)
         {
diff --git a/src/console/dlt-receive.c b/src/console/dlt-receive.c
index ef3ba20..ad8228b 100644
--- a/src/console/dlt-receive.c
+++ b/src/console/dlt-receive.c
@@ -435,9 +435,9 @@ int main(int argc, char* argv[])
     dlt_client_register_message_callback(dlt_receive_message_callback);
 
     /* Setup DLT Client structure */
-    dltclient.serial_mode = dltdata.yflag;
+    dltclient.mode = dltdata.yflag;
 
-    if (dltclient.serial_mode==0)
+    if (dltclient.mode==DLT_CLIENT_MODE_TCP)
     {
         for (index = optind; index < argc; index++)
         {
diff --git a/src/daemon/CMakeLists.txt b/src/daemon/CMakeLists.txt
index 70758cd..f665a4d 100644
--- a/src/daemon/CMakeLists.txt
+++ b/src/daemon/CMakeLists.txt
@@ -20,7 +20,7 @@ if(WITH_SYSTEMD_WATCHDOG OR WITH_SYSTEMD)
     message( STATUS "Added ${systemd_SRCS} to dlt-daemon")
 endif(WITH_SYSTEMD_WATCHDOG OR WITH_SYSTEMD)
 
-set(dlt_daemon_SRCS dlt-daemon.c dlt_daemon_common.c dlt_daemon_connection.c dlt_daemon_event_handler.c dlt_daemon_socket.c dlt_daemon_serial.c dlt_daemon_client.c dlt_daemon_offline_logstorage.c ${CMAKE_SOURCE_DIR}/src/shared/dlt_user_shared.c ${CMAKE_SOURCE_DIR}/src/shared/dlt_common.c ${CMAKE_SOURCE_DIR}/src/shared/dlt_shm.c ${CMAKE_SOURCE_DIR}/src/shared/dlt_offline_trace.c ${CMAKE_SOURCE_DIR}/src/offlinelogstorage/dlt_offline_logstorage.c ${CMAKE_SOURCE_DIR}/src/shared/dlt_config_file_parser.c)
+set(dlt_daemon_SRCS dlt-daemon.c dlt_daemon_common.c dlt_daemon_connection.c dlt_daemon_event_handler.c dlt_daemon_socket.c dlt_daemon_unix_socket.c dlt_daemon_serial.c dlt_daemon_client.c dlt_daemon_offline_logstorage.c ${CMAKE_SOURCE_DIR}/src/shared/dlt_user_shared.c ${CMAKE_SOURCE_DIR}/src/shared/dlt_common.c ${CMAKE_SOURCE_DIR}/src/shared/dlt_shm.c ${CMAKE_SOURCE_DIR}/src/shared/dlt_offline_trace.c ${CMAKE_SOURCE_DIR}/src/offlinelogstorage/dlt_offline_logstorage.c ${CMAKE_SOURCE_DIR}/src/shared/dlt_config_file_parser.c)
 add_executable(dlt-daemon ${dlt_daemon_SRCS} ${systemd_SRCS})
 target_link_libraries(dlt-daemon rt ${CMAKE_THREAD_LIBS_INIT})
 
diff --git a/src/daemon/dlt-daemon.c b/src/daemon/dlt-daemon.c
index 4e6b4b4..20dda80 100644
--- a/src/daemon/dlt-daemon.c
+++ b/src/daemon/dlt-daemon.c
@@ -31,6 +31,7 @@
 #include <ctype.h>
 #include <stdio.h>      /* for printf() and fprintf() */
 #include <sys/socket.h> /* for socket(), connect(), (), and recv() */
+#include <sys/un.h>
 #include <arpa/inet.h>  /* for sockaddr_in and inet_addr() */
 #include <stdlib.h>     /* for atoi() and exit() */
 #include <string.h>     /* for memset() */
@@ -56,6 +57,7 @@
 #include "dlt_daemon_common_cfg.h"
 
 #include "dlt_daemon_socket.h"
+#include "dlt_daemon_unix_socket.h"
 #include "dlt_daemon_serial.h"
 
 #include "dlt_daemon_client.h"
@@ -229,6 +231,9 @@ int option_file_parser(DltDaemonLocal *daemon_local)
 	memset(daemon_local->flags.pathToECUSoftwareVersion, 0, sizeof(daemon_local->flags.pathToECUSoftwareVersion));
 	daemon_local->flags.sendTimezone = 0;
 	daemon_local->flags.offlineLogstorageMaxDevices = 0;
+    strncpy(daemon_local->flags.ctrlSockPath,
+            DLT_DAEMON_DEFAULT_CTRL_SOCK_PATH,
+            sizeof(daemon_local->flags.ctrlSockPath) - 1);
 
 	/* open configuration file */
 	if(daemon_local->flags.cvalue[0])
@@ -420,6 +425,17 @@ int option_file_parser(DltDaemonLocal *daemon_local)
                         {
                             daemon_local->flags.offlineLogstorageMaxDevices = atoi(value);
                         }
+                         else if(strcmp(token,"ControlSocketPath")==0)
+                        {
+                            memset(
+                                daemon_local->flags.ctrlSockPath,
+                                0,
+                                DLT_DAEMON_FLAG_MAX);
+                            strncpy(
+                                daemon_local->flags.ctrlSockPath,
+                                value,
+                                DLT_DAEMON_FLAG_MAX-1);
+                        }
                         else
                         {
                             fprintf(stderr, "Unknown option: %s=%s\n",token,value);
@@ -753,6 +769,12 @@ int dlt_daemon_local_init_p2(DltDaemon *daemon, DltDaemonLocal *daemon_local, in
         dlt_log(LOG_ERR,"Could not initialize receiver for socket\n");
         return -1;
     }
+    if (dlt_receiver_init(&(daemon_local->receiverCtrlSock),
+                daemon_local->ctrlsock, DLT_DAEMON_RCVBUFSIZESOCK)==-1)
+    {
+        dlt_log(LOG_ERR,"Could not initialize receiver for control socket\n");
+        return -1;
+    }
     if (daemon_local->flags.yvalue[0])
     {
         if (dlt_receiver_init(&(daemon_local->receiverSerial),daemon_local->fdserial,DLT_DAEMON_RCVBUFSIZESERIAL) == DLT_RETURN_ERROR)
@@ -939,6 +961,16 @@ int dlt_daemon_local_connection_init(DltDaemon *daemon,
         return -1;
     }
 
+    /* create and open unix socket to receive incoming connections from
+     * control application */
+    if (dlt_daemon_unix_socket_open(
+                &(daemon_local->ctrlsock),
+                daemon_local->flags.ctrlSockPath))
+    {
+        dlt_log(LOG_ERR, "Could not initialize control socket.\n");
+        return -1;
+    }
+
     /* Init serial */
     if (dlt_daemon_init_serial(daemon_local) < 0)
     {
@@ -1502,6 +1534,136 @@ int dlt_daemon_process_client_messages_serial(DltDaemon *daemon, DltDaemonLocal
     return 0;
 }
 
+int dlt_daemon_process_control_connect(
+        DltDaemon *daemon,
+        DltDaemonLocal *daemon_local,
+        int verbose)
+{
+    socklen_t ctrl_size;
+    struct sockaddr_un ctrl;
+    int in_sock = -1;
+
+    PRINT_FUNCTION_VERBOSE(verbose);
+
+    if ((daemon==0)  || (daemon_local==0))
+    {
+        dlt_log(LOG_ERR, "Invalid function parameters used for function dlt_daemon_process_control_connect()\n");
+        return -1;
+    }
+
+    /* event from UNIX server socket, new connection */
+    ctrl_size = sizeof(ctrl);
+    if ((in_sock = accept(daemon_local->ctrlsock, &ctrl, &ctrl_size)) < 0)
+    {
+        dlt_log(LOG_ERR, "accept() on UNIX socket failed!\n");
+        return -1 ;
+    }
+
+    /* check if file file descriptor was already used, and make it invalid if it is reused */
+    /* This prevents sending messages to wrong file descriptor */
+    dlt_daemon_applications_invalidate_fd(daemon,in_sock,verbose);
+    dlt_daemon_contexts_invalidate_fd(daemon,in_sock,verbose);
+
+    if (dlt_connection_create(daemon_local,
+                             &daemon_local->pEvent,
+                             in_sock,
+                             EPOLLIN,
+                             DLT_CONNECTION_CONTROL_MSG))
+    {
+        dlt_log(LOG_ERR, "Failed to register new client. \n");
+        /* TODO: Perform clean-up */
+        return -1;
+    }
+
+    if (verbose)
+    {
+        snprintf(str,DLT_DAEMON_TEXTBUFSIZE, "New connection to client established, #connections: %d\n",
+                daemon_local->client_connections);
+        dlt_log(LOG_INFO, str);
+    }
+
+    return 0;
+}
+
+// FIXME: More or less copy of dlt_daemon_process_control_messages
+int dlt_daemon_process_control_messages(
+        DltDaemon *daemon,
+        DltDaemonLocal *daemon_local,
+        int verbose)
+{
+    int bytes_to_be_removed=0;
+
+    PRINT_FUNCTION_VERBOSE(verbose);
+
+    if ((daemon==0)  || (daemon_local==0))
+    {
+        dlt_log(LOG_ERR, "Invalid function parameters used for function dlt_daemon_process_control_messages()\n");
+        return -1;
+    }
+
+    if (dlt_receiver_receive_socket(&(daemon_local->receiverCtrlSock)) <= 0)
+    {
+        dlt_daemon_close_socket(daemon_local->receiverCtrlSock.fd,
+                                daemon,
+                                daemon_local,
+                                verbose);
+        daemon_local->receiverCtrlSock.fd = -1;
+        /* FIXME: Why the hell do we need to close the socket
+         * on control message reception ??
+         */
+        //return 0;
+    }
+
+    /* Process all received messages */
+    while (dlt_message_read(
+                &(daemon_local->msg),
+                (uint8_t*)daemon_local->receiverCtrlSock.buf,
+                daemon_local->receiverCtrlSock.bytesRcvd,
+                daemon_local->flags.nflag,
+                daemon_local->flags.vflag) == DLT_MESSAGE_ERROR_OK)
+    {
+        /* Check for control message */
+        if (daemon_local->receiverCtrlSock.fd > 0 &&
+            DLT_MSG_IS_CONTROL_REQUEST(&(daemon_local->msg)))
+        {
+            dlt_daemon_client_process_control(
+                    daemon_local->receiverCtrlSock.fd,
+                    daemon,daemon_local,
+                    &(daemon_local->msg),
+                    daemon_local->flags.vflag);
+        }
+
+        bytes_to_be_removed =
+            daemon_local->msg.headersize+daemon_local->msg.datasize -
+            sizeof(DltStorageHeader);
+
+        if (daemon_local->msg.found_serialheader)
+        {
+            bytes_to_be_removed += sizeof(dltSerialHeader);
+        }
+        if (daemon_local->msg.resync_offset)
+        {
+            bytes_to_be_removed += daemon_local->msg.resync_offset;
+        }
+
+        if (dlt_receiver_remove(&(daemon_local->receiverCtrlSock),bytes_to_be_removed)==-1)
+        {
+            dlt_log(LOG_WARNING,"Can't remove bytes from receiver for sockets\n");
+            return -1;
+        }
+
+    } /* while */
+
+
+    if (dlt_receiver_move_to_begin(&(daemon_local->receiverCtrlSock)) == -1)
+    {
+        dlt_log(LOG_WARNING,"Can't move bytes to beginning of receiver buffer for sockets\n");
+        return -1;
+    }
+
+    return 0;
+}
+
 int dlt_daemon_process_user_messages(DltDaemon *daemon, DltDaemonLocal *daemon_local, int verbose)
 {
     int offset=0;
diff --git a/src/daemon/dlt-daemon.h b/src/daemon/dlt-daemon.h
index 0e2fe37..ab18d1f 100644
--- a/src/daemon/dlt-daemon.h
+++ b/src/daemon/dlt-daemon.h
@@ -80,6 +80,7 @@
 #include <sys/time.h>
 
 #include "dlt_daemon_offline_logstorage.h"
+#define DLT_DAEMON_FLAG_MAX 256
 
 /**
  * The flags of a dlt daemon.
@@ -102,20 +103,21 @@ typedef struct
     char cvalue[NAME_MAX + 1];   /**< (String: Directory) Filename of DLT configuration file (Default: /etc/dlt.conf) */
     int  sharedMemorySize;       /**< (int) Size of shared memory (Default: 100000) */
     int  sendMessageTime;       /**< (Boolean) Send periodic Message Time if client is connected (Default: 0) */
-    char offlineTraceDirectory[256]; /**< (String: Directory) Store DLT messages to local directory (Default: /etc/dlt.conf) */
+    char offlineTraceDirectory[DLT_DAEMON_FLAG_MAX]; /**< (String: Directory) Store DLT messages to local directory (Default: /etc/dlt.conf) */
     int  offlineTraceFileSize;    /**< (int) Maximum size in bytes of one trace file (Default: 1000000) */
     int  offlineTraceMaxSize;    /**< (int) Maximum size of all trace files (Default: 4000000) */
     int  offlineTraceFilenameTimestampBased; /**< (int) timestamp based or index based (Default: 1 Timestamp based) */
     int  loggingMode;    /**< (int) The logging console for internal logging of dlt-daemon (Default: 0) */
     int  loggingLevel;    /**< (int) The logging level for internal logging of dlt-daemon (Default: 6) */
-    char loggingFilename[256]; /**< (String: Filename) The logging filename if internal logging mode is log to file (Default: /tmp/log) */
+    char loggingFilename[DLT_DAEMON_FLAG_MAX]; /**< (String: Filename) The logging filename if internal logging mode is log to file (Default: /tmp/log) */
     int  sendECUSoftwareVersion; /**< (Boolean) Send ECU software version perdiodically */
-    char pathToECUSoftwareVersion[256]; /**< (String: Filename) The file from which to read the ECU version from. */
+    char pathToECUSoftwareVersion[DLT_DAEMON_FLAG_MAX]; /**< (String: Filename) The file from which to read the ECU version from. */
     int  sendTimezone; /**< (Boolean) Send Timezone perdiodically */
     int  offlineLogstorageMaxDevices; /**< (int) Maximum devices to be used as offline logstorage devices */
     char userPipesDir[NAME_MAX + 1]; /**< (String: Directory) directory where dltpipes reside (Default: /tmp/dltpipes) */
     char daemonFifoName[NAME_MAX + 1]; /**< (String: Filename) name of local fifo (Default: /tmp/dlt) */
     unsigned int  port; /**< port number */
+    char ctrlSockPath[DLT_DAEMON_FLAG_MAX]; /**< Path to Control socket */
 } DltDaemonFlags;
 
 /**
@@ -127,12 +129,14 @@ typedef struct
     int fp;               /**< handle for own fifo */
     int sock;             /**< handle for tcp connection to client */
     int fdserial;         /**< handle for serial connection */
+    int ctrlsock;         /**< handle for control socket connection */
     DltFile file;             /**< struct for file access */
     DltEventHandler pEvent; /**< struct for message producer event handling */
     DltMessage msg;           /**< one dlt message */
     DltReceiver receiver;     /**< receiver for fifo connection */
     DltReceiver receiverSock; /**< receiver for socket connection */
     DltReceiver receiverSerial; /**< receiver for serial connection */
+    DltReceiver receiverCtrlSock; /**< receiver for control socket  */
     int client_connections;    /**< counter for nr. of client connections */
     size_t baudrate;          /**< Baudrate of serial connection */
 #ifdef DLT_SHM_ENABLE
@@ -187,6 +191,9 @@ int dlt_daemon_process_one_s_timer(DltDaemon *daemon, DltDaemonLocal *daemon_loc
 int dlt_daemon_process_sixty_s_timer(DltDaemon *daemon, DltDaemonLocal *daemon_local, int verbose);
 int dlt_daemon_process_systemd_timer(DltDaemon *daemon, DltDaemonLocal *daemon_local, int verbose);
 
+int dlt_daemon_process_control_connect(DltDaemon *daemon, DltDaemonLocal *daemon_local,int verbose);
+int dlt_daemon_process_control_messages(DltDaemon *daemon, DltDaemonLocal *daemon_local,int verbose);
+
 int dlt_daemon_process_user_message_overflow(DltDaemon *daemon, DltDaemonLocal *daemon_local, int verbose);
 int dlt_daemon_send_message_overflow(DltDaemon *daemon, DltDaemonLocal *daemon_local, int verbose);
 int dlt_daemon_process_user_message_register_application(DltDaemon *daemon, DltDaemonLocal *daemon_local, int verbose);
diff --git a/src/daemon/dlt.conf b/src/daemon/dlt.conf
index d9b0987..23d40ec 100644
--- a/src/daemon/dlt.conf
+++ b/src/daemon/dlt.conf
@@ -54,6 +54,11 @@ RingbufferMaxSize = 10000000
 RingbufferStepSize = 500000
 
 ########################################################################
+# Control Application                                                  #
+########################################################################
+ControlSocketPath = /tmp/dlt-ctrl.sock
+
+########################################################################
 # Offline Trace memory                                                 #
 ########################################################################
 
diff --git a/src/daemon/dlt_daemon_common_cfg.h b/src/daemon/dlt_daemon_common_cfg.h
index e0f99da..d08a20e 100644
--- a/src/daemon/dlt_daemon_common_cfg.h
+++ b/src/daemon/dlt_daemon_common_cfg.h
@@ -74,6 +74,7 @@
 /* Changable */
 /*************/
 
+
 /* Default Path for runtime configuration */
 #define DLT_RUNTIME_DEFAULT_DIRECTORY "/tmp"
 /* Path and filename for runtime configuration (applications) */
@@ -83,6 +84,10 @@
 /* Path and filename for runtime configuration */
 #define DLT_RUNTIME_CONFIGURATION     "/dlt-runtime.cfg"
 
+/* Default Path for control socket */
+#define DLT_DAEMON_DEFAULT_CTRL_SOCK_PATH DLT_RUNTIME_DEFAULT_DIRECTORY \
+                                          "/dlt-ctrl.sock"
+
 /* Size of text buffer */
 #define DLT_DAEMON_COMMON_TEXTBUFSIZE          255
 
@@ -120,4 +125,3 @@
 #define DLT_DAEMON_REMO_STRING "remo"
 
 #endif /* DLT_DAEMON_COMMON_CFG_H */
-
diff --git a/src/daemon/dlt_daemon_connection.c b/src/daemon/dlt_daemon_connection.c
index 0eee668..1a7af3f 100644
--- a/src/daemon/dlt_daemon_connection.c
+++ b/src/daemon/dlt_daemon_connection.c
@@ -200,6 +200,12 @@ static DltReceiver *dlt_connection_get_receiver(DltDaemonLocal *daemon_local,
         ret = &daemon_local->timer_wd;
         break;
 #endif
+    case DLT_CONNECTION_CONTROL_CONNECT:
+    /* FALL THROUGH */
+    /* There must be the same structure for this case */
+    case DLT_CONNECTION_CONTROL_MSG:
+        ret = &daemon_local->receiverCtrlSock;
+        break;
     default:
         ret = NULL;
     }
@@ -253,6 +259,12 @@ void *dlt_connection_get_callback(DltConnection *con)
         ret = dlt_daemon_process_systemd_timer;
         break;
 #endif
+    case DLT_CONNECTION_CONTROL_CONNECT:
+        ret = dlt_daemon_process_control_connect;
+        break;
+    case DLT_CONNECTION_CONTROL_MSG:
+        ret = dlt_daemon_process_control_messages;
+        break;
     default:
         ret = NULL;
     }
diff --git a/src/daemon/dlt_daemon_connection_types.h b/src/daemon/dlt_daemon_connection_types.h
index 4f4bb1c..c35b43e 100644
--- a/src/daemon/dlt_daemon_connection_types.h
+++ b/src/daemon/dlt_daemon_connection_types.h
@@ -39,6 +39,8 @@ typedef enum {
     DLT_CONNECTION_ONE_S_TIMER,
     DLT_CONNECTION_SIXTY_S_TIMER,
     DLT_CONNECTION_SYSTEMD_TIMER,
+    DLT_CONNECTION_CONTROL_CONNECT,
+    DLT_CONNECTION_CONTROL_MSG,
     DLT_CONNECTION_TYPE_MAX
 } DltConnectionType;
 
@@ -49,6 +51,8 @@ typedef enum {
 #define DLT_CON_MASK_ONE_S_TIMER        (1 << DLT_CONNECTION_ONE_S_TIMER)
 #define DLT_CON_MASK_SIXTY_S_TIMER      (1 << DLT_CONNECTION_SIXTY_S_TIMER)
 #define DLT_CON_MASK_SYSTEMD_TIMER      (1 << DLT_CONNECTION_SYSTEMD_TIMER)
+#define DLT_CON_MASK_CONTROL_CONNECT    (1 << DLT_CONNECTION_CONTROL_CONNECT)
+#define DLT_CON_MASK_CONTROL_MSG        (1 << DLT_CONNECTION_CONTROL_MSG)
 #define DLT_CON_MASK_ALL                (0xff)
 
 /* TODO: squash the DltReceiver structure in there
diff --git a/src/daemon/dlt_daemon_unix_socket.c b/src/daemon/dlt_daemon_unix_socket.c
new file mode 100644
index 0000000..05af5cb
--- /dev/null
+++ b/src/daemon/dlt_daemon_unix_socket.c
@@ -0,0 +1,109 @@
+/*
+ * @licence app begin@
+ * SPDX license identifier: MPL-2.0
+ *
+ * Copyright (C) 2015, Advanced Driver Information Technology
+ * Copyright of Advanced Driver Information Technology, Bosch and Denso
+ *
+ * This file is part of GENIVI Project DLT - Diagnostic Log and Trace.
+ *
+ * This Source Code Form is subject to the terms of the
+ * Mozilla Public License (MPL), v. 2.0.
+ * If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * For further information see http://www.genivi.org/.
+ * @licence end@
+ */
+
+/*!
+ * \author
+ * Christoph Lipka <clipka@jp.adit-jv.com>
+ *
+ * \copyright Copyright © 2015 ADIT. \n
+ * License MPL-2.0: Mozilla Public License version 2.0 http://mozilla.org/MPL/2.0/.
+ *
+ * \file dlt_daemon_unix_socket.c
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/un.h>
+#include <sys/socket.h>
+#include <syslog.h>
+#include <errno.h>
+#include "dlt-daemon.h"
+#include "dlt_common.h"
+#include "dlt-daemon_cfg.h"
+#include "dlt_daemon_socket.h"
+#include "dlt_daemon_unix_socket.h"
+
+char err_string[DLT_DAEMON_TEXTBUFSIZE];
+
+int dlt_daemon_unix_socket_open(int *sock, char *sock_path)
+{
+    struct sockaddr_un addr;
+
+    if (sock == NULL || sock_path == NULL)
+    {
+        dlt_log(LOG_ERR, "dlt_daemon_unix_socket_open: arguments invalid");
+        return -1;
+    }
+
+    if ((*sock = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
+    {
+        dlt_log(LOG_WARNING, "unix socket: socket() error");
+        return -1;
+    }
+
+    memset(&addr, 0, sizeof(addr));
+    addr.sun_family = AF_UNIX;
+    memcpy(addr.sun_path, sock_path, sizeof(addr.sun_path));
+
+    unlink(sock_path);
+
+    if (bind(*sock, (struct sockaddr *) &addr, sizeof(addr)) == -1)
+    {
+        dlt_log(LOG_WARNING, "unix socket: bind() error");
+        return -1;
+    }
+
+    if (listen(*sock, 1) == -1)
+    {
+        dlt_log(LOG_WARNING, "unix socket: listen error");
+        return -1;
+    }
+
+    return 0;
+}
+
+int dlt_daemon_unix_socket_close(int sock)
+{
+    int ret = close(sock);
+
+    if (ret != 0)
+    {
+        sprintf(err_string, "unix socket close failed: %s", strerror(errno));
+        dlt_log(LOG_WARNING, err_string);
+    }
+
+    return ret;
+}
+
+int dlt_daemon_unix_socket_send(
+        int sock,
+        void *data1,
+        int size1,
+        void *data2,
+        int size2,
+        char serialheader)
+{
+    /* re-use socket send function */
+    return dlt_daemon_socket_send(
+        sock,
+        data1,
+        size1,
+        data2,
+        size2,
+        serialheader);
+}
diff --git a/src/daemon/dlt_daemon_unix_socket.h b/src/daemon/dlt_daemon_unix_socket.h
new file mode 100644
index 0000000..5db4145
--- /dev/null
+++ b/src/daemon/dlt_daemon_unix_socket.h
@@ -0,0 +1,67 @@
+/*
+ * @licence app begin@
+ * SPDX license identifier: MPL-2.0
+ *
+ * Copyright (C) 2015, Advanced Driver Information Technology
+ * Copyright of Advanced Driver Information Technology, Bosch and Denso.
+ *
+ * This file is part of GENIVI Project DLT - Diagnostic Log and Trace.
+ *
+ * This Source Code Form is subject to the terms of the
+ * Mozilla Public License (MPL), v. 2.0.
+ * If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * For further information see http://www.genivi.org/.
+ * @licence end@
+ */
+
+/*!
+ * \author Christoph Lipka <clipka@jp.adit-jv.com>
+ *
+ * \copyright Copyright © 2015 ADIT. \n
+ * License MPL-2.0: Mozilla Public License version 2.0 http://mozilla.org/MPL/2.0/.
+ *
+ * \file dlt_daemon_unix_socket.h
+ */
+
+
+/*******************************************************************************
+**                                                                            **
+**  SRC-MODULE: dlt_daemon_unix_socket.h                                      **
+**                                                                            **
+**  TARGET    : linux                                                         **
+**                                                                            **
+**  PROJECT   : DLT                                                           **
+**                                                                            **
+**  AUTHOR    : Christoph Lipka clipka@jp.adit-jv.com                         **
+**                                                                            **
+**  PURPOSE   :                                                               **
+**                                                                            **
+**  REMARKS   :                                                               **
+**                                                                            **
+**  PLATFORM DEPENDANT [yes/no]: yes                                          **
+**                                                                            **
+**  TO BE CHANGED BY USER [yes/no]: no                                        **
+**                                                                            **
+*******************************************************************************/
+
+/*******************************************************************************
+**                      Author Identity                                       **
+********************************************************************************
+**                                                                            **
+** Initials     Name                       Company                            **
+** --------     -------------------------  ---------------------------------- **
+**  cl          Christoph Lipka            ADIT                               **
+*******************************************************************************/
+
+#ifndef DLT_DAEMON_UNIX_SOCKET_H
+#define DLT_DAEMON_UNIX_SOCKET_H
+
+int dlt_daemon_unix_socket_open(int *sock, char *socket_path);
+int dlt_daemon_socket_close(int sock);
+
+int dlt_daemon_unix_socket_send(int sock,void* data1,int size1,void* data2,
+        int size2,char serialheader);
+
+#endif /* DLT_DAEMON_UNIX_SOCKET_H */
diff --git a/src/lib/dlt_client.c b/src/lib/dlt_client.c
index 2bae2eb..3de3845 100644
--- a/src/lib/dlt_client.c
+++ b/src/lib/dlt_client.c
@@ -77,6 +77,7 @@
 #include <arpa/inet.h>  /* for sockaddr_in and inet_addr() */
 #include <netdb.h>
 #include <sys/stat.h>
+#include <sys/un.h>
 #endif
 
 #if defined(_MSC_VER)
@@ -116,7 +117,8 @@ DltReturnValue dlt_client_init(DltClient *client, int verbose)
     client->servIP = 0;
     client->serialDevice = 0;
     client->baudrate = DLT_CLIENT_INITIAL_BAUDRATE;
-    client->serial_mode = 0;
+    client->socketPath = 0;
+    client->mode=DLT_CLIENT_MODE_TCP;
     client->receiver.buffer = 0;
 
     return DLT_RETURN_OK;
@@ -126,6 +128,7 @@ DltReturnValue dlt_client_connect(DltClient *client, int verbose)
 {
     char portnumbuffer[33];
     struct addrinfo hints, *servinfo, *p;
+    struct sockaddr_un addr;
     int rv;
     char *env_daemon_port;
    /* the port may be specified by an environment variable, defaults to DLT_DAEMON_TCP_PORT */
@@ -149,8 +152,9 @@ DltReturnValue dlt_client_connect(DltClient *client, int verbose)
       servPort = DLT_DAEMON_TCP_PORT;
     }
 
-    if (client->serial_mode==0)
+    switch (client->mode)
     {
+    case DLT_CLIENT_MODE_TCP:
         snprintf(portnumbuffer, 32, "%d", servPort);
         if ((rv = getaddrinfo(client->servIP, portnumbuffer, &hints, &servinfo)) != 0) {
             fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
@@ -182,9 +186,8 @@ DltReturnValue dlt_client_connect(DltClient *client, int verbose)
         {
             printf("Connected to DLT daemon (%s)\n",client->servIP);
         }
-    }
-    else
-    {
+        break;
+    case DLT_CLIENT_MODE_SERIAL:
         /* open serial connection */
         client->sock=open(client->serialDevice,O_RDWR);
         if (client->sock<0)
@@ -218,6 +221,39 @@ DltReturnValue dlt_client_connect(DltClient *client, int verbose)
         {
             printf("Connected to %s\n", client->serialDevice);
         }
+        break;
+    case DLT_CLIENT_MODE_UNIX:
+        if ((client->sock = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
+        {
+            fprintf(stderr, "ERROR: (unix) socket error: %s\n", strerror(errno));
+            return DLT_RETURN_ERROR;
+        }
+
+        memset(&addr, 0, sizeof(addr));
+        addr.sun_family = AF_UNIX;
+        memcpy(addr.sun_path, client->socketPath, sizeof(addr.sun_path)-1);
+
+        if (connect(client->sock,
+                    (struct sockaddr_un *)&addr,
+                    sizeof(addr)) == -1)
+        {
+            fprintf(stderr, "ERROR: (unix) connect error: %s\n", strerror(errno));
+            return DLT_RETURN_ERROR;
+        }
+
+        if (client->sock < 0)
+        {
+            fprintf(stderr,"ERROR: Failed to open device %s\n",
+                    client->socketPath);
+            return DLT_RETURN_ERROR;
+        }
+        break;
+    default:
+        if (verbose)
+        {
+            fprintf(stderr, "ERROR: Mode not supported: %d\n", client->mode);
+        }
+        return DLT_RETURN_ERROR;
     }
 
     if (dlt_receiver_init(&(client->receiver),client->sock,DLT_CLIENT_RCVBUFSIZE) != DLT_RETURN_OK)
@@ -271,7 +307,7 @@ DltReturnValue dlt_client_main_loop(DltClient *client, void *data, int verbose)
 
     while (1)
     {
-        if (client->serial_mode==0)
+        if (client->mode==0)
         {
             /* wait for data from socket */
             ret = dlt_receiver_receive_socket(&(client->receiver));
@@ -437,7 +473,7 @@ DltReturnValue dlt_client_send_ctrl_msg(DltClient *client, char *apid, char *cti
     msg.standardheader->len = DLT_HTOBE_16(len);
 
     /* Send data (without storage header) */
-    if (client->serial_mode)
+    if (client->mode)
     {
         /* via FileDescriptor */
         ret=write(client->sock, msg.headerbuffer+sizeof(DltStorageHeader),msg.headersize-sizeof(DltStorageHeader));
diff --git a/src/tests/dlt-test-client.c b/src/tests/dlt-test-client.c
index 83a6fe6..9df7e3e 100644
--- a/src/tests/dlt-test-client.c
+++ b/src/tests/dlt-test-client.c
@@ -277,9 +277,9 @@ int main(int argc, char* argv[])
     dlt_client_register_message_callback(dlt_testclient_message_callback);
 
     /* Setup DLT Client structure */
-    dltclient.serial_mode = dltdata.yflag;
+    dltclient.mode = dltdata.yflag;
 
-    if (dltclient.serial_mode==0)
+    if (dltclient.mode==0)
     {
         for (index = optind; index < argc; index++)
         {
diff --git a/src/tests/dlt-test-multi-process-client.c b/src/tests/dlt-test-multi-process-client.c
index c943578..bdefaaa 100644
--- a/src/tests/dlt-test-multi-process-client.c
+++ b/src/tests/dlt-test-multi-process-client.c
@@ -166,7 +166,7 @@ int init_dlt_connect(DltClient *client, const s_parameters *params, int argc, ch
         return -1;
     if(params->serial > 0)
     {
-        client->serial_mode = 1;
+        client->mode = 1;
         client->serialDevice = argv[argc - 1];
         dlt_client_setbaudrate(client, params->baudrate);
     }
@@ -203,7 +203,7 @@ int main(int argc, char *argv[]) {
 
     err = dlt_client_connect(&client, params.verbose);
     if (err != DLT_RETURN_OK) {
-            printf("Failed to connect %s.\n", client.serial_mode > 0 ? client.serialDevice : client.servIP);
+            printf("Failed to connect %s.\n", client.mode > 0 ? client.serialDevice : client.servIP);
         return err;
     }
 
diff --git a/src/tests/dlt-test-stress-client.c b/src/tests/dlt-test-stress-client.c
index fc62230..e0ca808 100644
--- a/src/tests/dlt-test-stress-client.c
+++ b/src/tests/dlt-test-stress-client.c
@@ -298,9 +298,9 @@ int main(int argc, char* argv[])
     dlt_client_register_message_callback(dlt_testclient_message_callback);
 
     /* Setup DLT Client structure */
-    dltclient.serial_mode = dltdata.yflag;
+    dltclient.mode = dltdata.yflag;
 
-    if (dltclient.serial_mode==0)
+    if (dltclient.mode==0)
     {
         for (index = optind; index < argc; index++)
         {
diff --git a/tests/dlt_test_receiver.c b/tests/dlt_test_receiver.c
index a0e86f7..9b93728 100644
--- a/tests/dlt_test_receiver.c
+++ b/tests/dlt_test_receiver.c
@@ -235,9 +235,9 @@ int main(int argc, char* argv[])
     dlt_client_register_message_callback(dlt_receive_filetransfer_callback);
 
     /* Setup DLT Client structure */
-    dltclient.serial_mode = dltdata.yflag;
+    dltclient.mode = dltdata.yflag;
 
-    if (dltclient.serial_mode==0)
+    if (dltclient.mode==0)
     {
         for (index = optind; index < argc; index++)
         {